title: A plant-specific transcription factor IIB-related protein, pBRP2, is involved in endosperm growth control.
abstract: General transcription factor IIB (TFIIB) and TFIIB-related factor (BRF), are conserved RNA polymerase II/III (RNAPII/III) selectivity factors that are involved in polymerase recruitment and transcription initiation in eukaryotes. Recent findings have shown that plants have evolved a third type of B-factor, plant-specific TFIIB-related protein 1 (pBRP1), which seems to be involved in RNAPI transcription. Here, we extend the repertoire of B-factors in plants by reporting the characterization of a novel TFIIB-related protein, plant-specific TFIIB-related protein 2 (pBRP2), which is found to date only in the Brassicacea family. Unlike other B-factors that are ubiquitously expressed, PBRP2 expression is restricted to reproductive organs and seeds as shown by RT-PCR, immunofluorescence labelling and GUS staining experiments. Interestingly, pbrp2 loss-of-function specifically affects the development of the syncytial endosperm, with both parental contributions required for wild-type development. pBRP2, is the first B-factor to exhibit cell-specific expression and regulation in eukaryotes, and might play a role in enforcing bi-parental reproduction in angiosperms.
authors.affiliation: Laboratoire Génome et Développement des Plantes, Centre National de la Recherche Scientifique/Institut de Recherche pour le Développement/Université de Perpignan, Perpignan, France.
authors.forename: Emilie
authors.initials: E
authors.lastname: Cavel
authors.forename: Marion
authors.initials: M
authors.lastname: Pillot
authors.forename: Dominique
authors.initials: D
authors.lastname: Pontier
authors.forename: Sylvie
authors.initials: S
authors.lastname: Lahmy
authors.forename: Natacha
authors.initials: N
authors.lastname: Bies-Etheve
authors.forename: Danielle
authors.initials: D
authors.lastname: Vega
authors.forename: Daniel
authors.initials: D
authors.lastname: Grimanelli
authors.forename: Thierry
authors.initials: T
authors.lastname: Lagrange
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics; D019607:Brassicaceae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D056625:Endosperm / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D030821:Plants, Genetically Modified; D012639:Seeds / Q000235:genetics / Q000254:growth & development; D017385:Sequence Homology; D013045:Species Specificity; D035581:Transcription Factor TFIIB / Q000737:chemistry; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; D010940:Plant Proteins; D035581:Transcription Factor TFIIB; D014157:Transcription Factors; C474201:transcription factor IIB-related protein, Arabidopsis